Heat exchanger

ABSTRACT

A heat exchanger apparatus for exchange of heat between two fluids which is especially adaptable for use as an oil cooler in an internal combustion engine with the apparatus comprising a stack of successive pairs of metal plates shaped and bonded together and enclosed in a casing, the stack of plates being shaped to prvide interconnected passages for a first fluid such as the oil to be cooled, surrounding passages for a second fluid such as the liquid coolant from an internal combustion engine, and means for flowing the oil and the coolant through their respective passages to and from the engine.

United States Patent Frost [451 July 3, 1973 HEAT EXCHANGER 3.353.59011/1967 Holman 165/35 [75] lnventor: Donald J. Frost, Racine, Wis.Primary Examiner chafles m [73] Assignee: giggle lailsnufacturingCompany, jjgifgfgi'g zraggigg g :3 Streule [22] Filed: Nov. 4, 1971ABSTRACT [21] Appl. No.: 195,680

Related US. Application Data [63] Continuation-impart of Ser. No.23,191, March 27,

1970, abandoned.

[52] US. Cl. 165/38, 165/167 [51] Int. Cl FZSf 3/00 [58] Field of Search165/164-166, 167, 35-38 [56] References Cited UNITED STATES PATENTS2,251,066 7/1941 Persson et a] 165/167 2,511,084 6/1950 Shaw 165/166 Aheat exchanger apparatus for exchange of heat between two fluids whichis especially adaptable for use as an oil cooler in an internalcombustion engine with the apparatus comprising a stack of successivepairs of metal plates shaped and bonded together and enclosed in acasing, the stack of plates being shaped to prvide interconnectedpassages for a first fluid such as the oil to be cooled, surroundingpassages for a second fluid such as the liquid coolant from an internalcombustion engine, and means for flowing the oil and the coolant throughtheir respective passages to and from the engine.

19 Claims, 14 Drawing Figures 'PAIENIEDJUL3 1915 I 3.743 011 SHEET 10F 4PAIENTED JUL 3 I973 SHEEI 3 BF 4 \YON HEAT EXCHANGER CROSS REFERENCE TORELATED APPLICATION This application is a continuation-in-part of mycopending application Ser. No. 23,191, filed Mar. 27, 1970 nowabandoned.

SUMMARY OF THE INVENTION One of the features of this invention is toprovide a heat exchanger apparatus having the structure set out above.

In one embodiment the heat exchanger apparatus when used to cool enginelubricating oil has means thereon for mounting an oil filter with flowconnections for passage of the oil through the filter and preferablyprior to passage of the oil through the oil cooling portions of the heatexchanger.

In a more specific embodiment of the invention a central conduit of theheat exchanger is used to mount the exchanger on the engine block, tomount the filter on the heat exchanger when a filter is used, to mount acover plate in place of the filter when one is not used and to contain abypass valve that permits passage of cold oil directly back to theengine without substantial flow through the oil cooling portion of theapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational viewpartially broken away of an engine block having mounted thereon a heatexchanger oil cooler apparatus embodying the invention with an oilfilter of the customary type in position.

FIG. 2 is a view similar to FIG. 1 but with an enclosing cap replacingthe oil filter of FIG. 1.

FIG. 3 is a plan view of the heat exchanger partially broken away andomitting both the filter of FIG. 1 and the cap of FIG. 2.

FIG. 4 is an enlarged longitudinal sectional view through the heatexchanger apparatus embodying the invention.

FIG. 5 is a plan view of one of a plurality of cooperating fluid flowplates used in the heat exchanger.

FIG. 6 is an edge elevational view of the plate of FIG. 5.

FIG. 7 is an enlarged transverse sectional view taken substantiallyalong line 77 of FIG. 5.

FIG. 8 is a plan view of an agitator or turbulizer fin used between eachadjacent pair of plates.

FIG. 9 is an enlarged plan view of a detail portion of FIG. 8.

FIG. 10 is a sectional view taken substantially along line 1010 of FIG.9.

FIG. 11 is a view similar to FIG. 4 but illustrating a second embodimentof the invention.

FIG. 12 is a view similar to FIG. 5 but illustrating a plate of thissecond embodiment.

FIG. 13 is a sectional view taken along line 1313 of FIG. 12.

FIG. 14 is a sectional view taken along line 14-14 of FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in the drawingsthe heat exchanger apparatus 10 of this invention is shown as mounted onan engine block 11 in communication with a lubricating oil passage 12therefrom and a second oil passage 13 leading back into the block. Inaddition, as illustrated in FIGS. 1 and 2, the engine block containsoutlet and inlet passages for flow of liquid coolant from the coolantcontaining portions of the block directly to and from the heat exchanger10 as illustrated by the broken line connections 14 and 15 of FIGS. 1and 2 as well as the liquid conduits of FIG. 3.

The apparatus although illustrated as being used to cool lubricating oilin an engine by using liquid coolant directly from the engine can alsobe used for exchange of heat between any two fluids. The heat exchangerof the first embodiment of FIGS. 1-10 comprises a plurality ofsuccessive pairs of metal plates 16 that are arranged in a stack havinga generally cylindrical outer configuration. Each plate 16 has an outeredge 17 and an inner opening defined by an inner edge 18. Eachsuccessive pair of plates is joined at first areas 19 adjacent theirinner edges 18 and at second areas 20 inwardly of the plate outer edges17.

Each of the stacked pairs of plates is spaced apart between the first l9and second 20 joined areas to provide a first chamber 21 in each pair ofplates. Because there are successive pairs of plates arranged in thestack as shown in FIG. 4 there are of course a plurality of successivechambers 21.

Also provided are means joining adjacent plates in each of the stackedpairs of plates at third areas 22 with these third areas being locatedoutwardly of the second areas and in the embodiment illustrated aroundthe periphery of the assembly of plates.

The second joined areas 20 of the plates are spaced apart as illustratedat the bottom of FIG. 4 and thereby provide a succession of peripherallylocated second chambers 23. Fluid flow opening means 24 are located inthese second areas 20 joining the series of second chambers 23 toprovide a flow manifold 25.

Each successive pair of plates 16 is spaced apart inwardly of the joinedthird areas 22 to provide a succession of third chambers 26 thatcommunicate at their outer ends with the second chambers 23 and that areopen at their inner ends as illustrated at 27.

As will be described in more detail herein, means are provided forflowing a first fluid, in the illustrated embodiment engine lubricatingoil, radially outwardly through one group of third chambers 26 by way oftheir open inner ends 27 and radially inwardly through a second group ofthese third chambers 26 to their open inner ends 27 with the flow beingby way of the first manifold 25 and also means for flowing a secondfluid, in this embodiment liquid coolant from the engine, through thefirst chambers 21.

In the preferred apparatus the means joining the pairs of plates attheir first areas 19 extend completely around the inner edges of thestack of plates thereby providing an inner flow passage means 28. Meansare provided for dividing this inner flow passage means into twoadjacent parts with one part 29 communicating with the one group ofthird chambers 26 and a second part 30 communicating with a second groupof these chambers 26. In the embodiment disclosed this dividing means isembodied in a fluid flow conduit or pipe 31 extending through the innerflow passage 28 with this pipe having a first series of three circularlyarranged openings 32 leading directly to the one flowpassage part 29 anda second series of three circularly arranged openings 33 adjacent thesecond flow passage part 30. The openings 32 and 33 are axially spacedfrom each other along the pipe 31 and are located on opposite sides ofan annular boss 34 on the outside of the pipe 31 and positioned at themidpoint of the flow passage 28 to divide it into the first part 29 andthe second part 30.

In the illustrated first embodiment of the heat exchanger the joinedsecond areas 20 are of small extent and arcuately extended as shown inFIG. 5 with the resulting fluid flow openings 24 being of similar shape.As is shown in FIG. 5 there are a plurality of these second areas 20,here shown as three, arcuately spaced around each plate 16 adjacent theperiphery thereof. As illustrated, the areas 20 and their containedopenings are spaced about 120 apart.

There are also provided means joining adjacent plates 16 of each of thestacked pairs of plates as illustrated in FIG. 4 at an enclosing fourtharea 35 and with each of the joined pairs of fourth areas being spacedfrom the adjacent joined pair of fourth areas to provide a succession ofperipherally located fourth chambers 36 that are connected by openings37 thereby providing a second manifold 38. The areas 66 of plates 16surrounding openings 37 are also joined together to provide a fluidtight structure.

The assembly of joined pairs of plates 16 are capped at their oppositeends by an end plate 39 adjacent the engine block 1 1 and an oppositeend plate 40 at the opposite end. In the illustrated embodiment thereare three sets of second manifolds 38 also arranged 120 apart andsymmetrically arranged with respect to each other to the three firstmanifolds previously described. In order to provide for flow of a firstfluid such as the illustrated engine lubricating oil through the threesecond manifolds 38 there are provided in the end plate 39 threeopenings 41 each leading directly into a manifold 38 as illustrated inFIG. 4 while the opposite end plate 40 is provided with three similaropenings 42 for flow of fluid from the three second manifolds 38. Thuswith this arrangement in the illustrated embodiment the flow of fluid oroil from the engine block 11 is in three parallel paths comprising thethree manifolds 38.

The assembly of stacked plates 16 is enclosed in a generally cylindricalcasing 43 that has an edge 44 joined to the outer edge of the first endplate 39. The opposite end 45 of the casing 43 is spaced from the endplate 40 so as to provide an annular chamber 46. The three manifolds 38empty into this annular chamber by way of the aligned openings 42.

The liquid coolant is conducted from the coolant containing portions ofthe engine block 11 by way of the previously described coolantconnecting lines 14 and 15. In its flow through the heat exchanger thecoolant flows through the first chamber 21 and around the three firstmanifolds 25 as well as around the three second manifolds 38 beforereturning to the coolant section of the engine block 11. This flowthrough the spaced chambers 21 and around the total of six manifoldsprovides very efficient cooling of the oil that is at the same timeflowing through the assembly of third chambers 26. As is obvious, eachthird chamber 26 that forms a portion of the oil flow passage issurrounded by the first chamber 21 which contains the liquid coolant.

In order to further increase the coolant efficiency each third chamber26 contains an annular agitator or turbulizer fin 47 that is illustratedin detail in FIGS. 8, 9 and 10. As is shown in FIG. 8, each fin 47 is ametal plate that is generally circular with an inner circular opening 48that substantially coincides with the inner end 27 of the third chamber26 in which the fin 47 is located. The outer periphery of each fin 47 isprovided with three symmetrically arranged recesses 49 each of which isarranged on the outside of one of the three second manifolds 38.

As is illustrated in the enlarged details of FIGS. 9 and 10 each fin 47comprises a plate having one set of spaced projections 63 extending outof the plane 50 of the plate on one side thereof and another set ofprojections 51 extending from the other side of the plane 50 of theplate and with certain of the projection 63 and 51 as illustrated inFIG. 10 being joined directly as indicated at 52. In the illustratedembodiment each'projection 63 and 51 of each fin 47 is of essentiallyfrustoconical shape with the peak of each projection being positionedagainst an enclosing plate 16 as illustrated in FIG. 4.

As illustrated the heat exchanger of this invention for exchanging heatbetween two fluids is ideally designed for cooling lubricating oil froman engine by use of the liquid coolant directly from the engine. Theheat exchanger is easily mounted on the engine block 11 by having oneend 52 of the pipe or conduit 31 threaded directly to the block inalignment with the other passage 13 in the block. The edge 44 of thecooler will then enclose the other oil passage 12 as illustrated in FIG.4 and at the same time retain in position a surrounding O-ring gasket 53to prevent oil leakage between the heat exchanger and the engine block.

The opposite end 54 of the pipe 31 can also extend beyond the heatexchanger and contains attaching means, here shown as threads 54, forattaching either an oil filter 55 as shown in FIG. 1 or an enclosingdished cap 56 as illustrated in FIG. 2. This end also holds a nut 64retainer for the heat exchanger plates 16. In either case the oil filter55 or cap 56 holds in position a second O-ring gasket 57 as shown ineach of FIGS. 1 and 2 that surrounds the exit passages 58 leading fromthe annular chamber 46. Whether the oil filter 55 is used or merely theenclosing cap 56 the oil will flow outwardly of the block 11 through thepassage 12 and through the three sets of second manifolds 38 in parallelflow through the exchanger. From the manifolds 38 the oil flows throughthe openings 42 into the chamber 46 and from there through the openings58 either through the oil filter 55 or into the cap 56.

The oil is then directed from either the filter 55 or the cap 56 intothe interior of the pipe 31 for return to the engine by way of thepassage 13. If the oil is cold and therefore with a relatively highviscosity it displaces a bypass valve 60 for flow directly through thepipe 31 into the return passage 13, bypassing the heat exchangerchambers 26. This bypass valve will now be described.

The interior of the pipe 31 at about the region of the annular boss 34is provided with an annular valve seat 59 for a spring pressed circularvalve 60. This valve 60 is held in position on the seat 59 by a helicalcompression spring 61 one end of which bears against the valve 60 andthe other end of which bears against a cross pin 62 that extends acrossthe interior of the pipe 31. Thus with this arrangement the valve 60 islocated between the two sets of openings 32 and 33.

When the oil flowing inwardly (arrow 65) through the pipe 31 is cold andviscous it exerts sufficient pressure on the valve 60 to displace itagainst the thrust of the spring 61 and permit the oil to flow aroundthe valve 60 and directly into the return passage 13 without flowingthrough the oil cooling passages. When, however, the oil has becomesufficiently heated to have a reduced viscosity it cannot then overcomethe pressure of the spring 61 so that the valve 60 closes. In onetypical embodiment of this invention the spring 61 was designed to closeat about pounds per square inch pressure.

With the valve 60 closed by the spring 61 the oil thereupon flowsradially outwardly through the set of three openings 32 and through thefirst set of oil flow chambers 26 and into the corresponding chambers 23of the first manifold 25. These are of course the chambers 26 on theupstream side of the boss 34. Then the oil flows through the three firstmanifolds 26 into the remaining oil cooling chambers 26 which are on thedownstream side of the boss 34. Here the oil flows radially inwardlytoward the pipe 31, through the three circularly arranged openings 33and then axially into the engine by way of the passage 13.

During the flow of the oil in the chambers 26 which is first radiallyoutwardly and then radially inwardly the oil is cooled by thesurrounding coolant in the series of first chambers 21 and this coolingis more efficiently accomplished by reason of the agitator fin 47 ineach chamber 26 which causes a turbulent flow.

The heat exchanger of this invention is very efficient in exchangingheat between two flowing fluids and occupies very small space. Thesegeneral characteristics make it extremely useful as an oil cooler forcooling the oil of an engine and it can be mounted directly on the blockso as to permit oil and coolant directly from the engine to flow throughthe heat exchanger and back to the engine. Furthermore, in oneembodiment as illustrated in FIG. 1 the cooler serves as a mounting foran oil filter so that a separate mounting is not required and when thefilter is used it permits preferably flowing the oil through the filterto remove any solid foreign particles before the oil is conveyed throughthe cooling portion of the apparatus.

Because the heat exchanger receives coolant directly from the engine andnot from a radiator its performance is not controlled by the usualengine thermostat which controls flow through a radiator. This flow ofcoolant directly from the engine provides warm coolant at the verybeginning of operation of the engine so that the viscosity of the oil isimmediately lowered for flow of this decongealed oil through the coolerpassages rapidly and efficiently.

As can be seen from the detailed description given above of theconstruction of the exchanger, the device is made up entirely ofassembled sheet metal parts some of which are plates held in positionwithin an enclosing casing. The exchanger includes a conduit 31 thatalso serves as a means for mounting the exchanger on the engine blockand for mounting an oil filter where one is used or a flow directing capin place of the filter.

FIGS. 11-14 illustrate a second embodiment of the invention in which oilflows through the cooler apparatus 110 and then passes on to the filteras shown at 55 in the first embodiment or the return cap 56 also shownin this first embodiment and with the second embodiment in additionproviding a bypass through which the oil may flow without being cooledwhere cooling is not required. In this second embodiment there are thesame coolant connections as in the first embodiment and with these beingindicated generally at in FIG. 11. As indicated, the liquid coolantflows into the apparatus as indicated at 70 and from the apparatus asshown at 71.

The heat exchanger itself comprises a series of plates 116 arranged insuccessive pairs with each pair having outer edges 117 joined togetheras illustrated in FIG. 11 and inner edges 118 that are interconnected soas to comprise joined first areas 119. Each adjacent pair of plates 116are also joined at second areas inwardly of the outer edges and each ofthe pairs of plates are spaced apart between their first 119 and second120 areas to provides a series of first chambers 121 as illustrated onthe right side of FIG. 1 1. In the illustrated embodiment these firstchambers 121 receive coolant that flows through the enclosing casing 143to cool the oil flowing through the heat exchanger in the manner to bedescribed in greater detail hereinafter.

The stacked pairs of plates are joined at third areas 117 locatedoutwardly of the second areas 120. These second areas 120 are spacedapart in the successive pairs of plates to provide a succession ofperipherally located second chambers 123. Fluid flow opening means 124are provided in these second areas to provide a flow manifold 125joining the second chambers 123 in series as shown at the left side ofFIG. 11.

The successive pairs of plates 116 are spaced apart inwardly of thethird areas 117 to provide a series of third chambers 126 each of whichcommunicates with a corresponding second chamber 123 and these thirdchambers 126 are open at their inner ends or edges to fourth chambers136 provided between the adjacent plates of adjacent pairs as shown atthe right side of FIG. 11.

These fourth chambers 136 comprise means for flowing a first fluid, suchas oil in the illustrated embodiment, radially outwardly through onegroup of third chambers 126 by way of openings 137 in the adjacent pairsof plates. At the outer extremities of these third chambers 126 whichreceive oil directly from the fourth chambers 136 the interconnection tothe second chambers 123 of the manifold 125 provides for flowing the oilthen radially inwardly through the second set or group of oil flow thirdchambers 126 which in FIG. 11 are above the dividing partition 73.

The heat exchanger also provides means for flowing a second fluidthrough the first chambers 121 which in this embodiment is liquidcoolant within the enclosing casing 143. In order to provide for flow ofcoolant for the second fluid through the first chambers 121 each plate116 is provided with the series of raised areas 86 as shown in FIG. 12.These raised areas which are of small extent have flat tops which areinterconnected in adjacent plates of successive pairs of plates as shownin FIG. 11 so as to hold these successive plates apart in peripheralareas. Thus as shown in FIG. 14 one side of each plate 116 which here isthe left side forms a boundary for the coolant containing first chambers121 while the opposite sides form the boundary of the oil containingthird chambers 126. In order to indicate these respective sides of theplate the sides are identified with the numerals 121 and 126 in FIG. 14.

The assembly of plates are arranged in a stack as shown in FIG. 11 andthe stack is assembled in a pluralv ity of sets, here shown as two, witheach set being separated from the other by the transverse partition 73.This partition is provided with one opening 74 forming a part of theflow manifold 125 and with a second opening 75 which will be describedin more detail hereinafter.

In the second chambers 123 and third chambers 126 there are providedagitator fins 147 similar to the fins 47 shown in detail in the firstembodiment.

In order to separate the cooling flow path and the bypass non-coolingflow path each plate 116 is provided with a continuous ridge 76enclosing the bypass path 77 portion of the plates and the openings 85in which is located the pipe 131. In the assembled plates the peaks ofthese ridges are joined as indicated at FIG. 11 and thereby enclose thebypass path 77 and separate it from the cooling oil path 72 whichincludes the third chambers 126 and the interconnected second chambers123. Oil flow in this bypass path is indicated by the dotted line arrows79 in FIG. 11.

The enclosing casing 143 through which the coolant 70 is directed has anend plate 145 on the end opposite the plate 139 and containing a plenumchamber 158 having flow openings 80 for both the oil path flow and alsothe bypass path flow.

Aligned with the openings 75 in the partition 73 are a series ofopenings 81 in the plates. Located in the space provided by theseopenings and in the bottom half of the heat exchanger is a bypass valvestructure 82 similar to the valve 60, spring 61 and cross pin 62 of thefirst embodiment as illustrated in FIG. 4. This bypass valve operates inthe same manner as in the first embodiment and therefore opens when theoil is cold enough not to require cooling so that the oil can flowdirectly through the bypass path 77 into the filter or into the returncap as illustrated in F168. 1 and 2.

The heat exchanger or oil cooler of the second embodiment operates asfollows. Coolant such as the coolant liquid of the engine is circulatedthrough the casing 143 and the coolant first chambers 121 as in thefirst embodiment. Lubricating oil when cooling-is required flows throughthe third chambers 126 and manifold second chambers 123 as indicated bythe arrows 72 of FIG. 1 1. While flowing through these chambers the oilpasses through and around the assembled turbulizer fins 147 foragitation and better heat transfer. In the disclosed embodiment the oilflows in parallel through the cooling chambers beneath the partition 73and then passes from the flow manifold 124 through the openings 74 inthe partition to the second set of cooling chambers that are above thepartition of FIG. 11. From here the oil then flows through an endopening 84 in an end plate 140 and into either the oil filter of thetype illustrated in FIG. 1 or into the return cap shown at 56 in FIG. 2if an oil filter is not used. The oil then flows back through thefitting or pipe 131 to the engine as indicated by the arrows 165.

In the event the oil is so cold that no cooling is required the highviscosity of the oil will open the valve 82 so that the oil is directedin the bypass path and without flowing through the cooler itself, all inthe same manner as described in the first embodiment.

ln spite of the compact size of the heat exchanger it provides flow ofoil in parallel passages radially outwardly and then radially inwardlywith these passages each being surrounded by coolant and with eachpassage preferably containing an agitator or turbulizer fin. This typeof oil flow separated into the two paths arrangement permits attaininghigh heat transfer between the oil and the coolant with a low pressuredrop through the exchanger because the total length of the parallel flowis quite short.

The heat exchanger of this invention is also adaptable to existing oilfilter locations and is readily accessible for rapid replacement orrepair and can be easily removed for cleaning. It has an attractiveappearance and can be used as a supplement to an existing oil coolerwhere greater cooling capacity is required or desired.

Having described my invention as related to the embodiment shown in theaccompanying drawings, it is my intention that the invention be notlimited by any of the details of description, unless otherwisespecified, but rather be construed broadly within its spirit and scopeas set out in the appended claims.

I claim:

1. Heat exchanger apparatus for exchange of heat between two fluids,comprising: a plurality of successive pairs of plates arranged in astack, each said plate having an outer edge and an inner openingdefining an inner edge; means joining each pair of plates at first areasadjacent their inner edges and at second areas inwardly of their outeredges, each said pair of plates being spaced apart between their saidfirst and second areas thereby providing a first chamber in each pair;means joining adjacent plates of each of said stacked pairs of plates atthird areas located outwardly of said second areas, said second areas ofsuccessive pairs of plates being spaced apart thereby providing asuccession of peripherally located second chambers; fluid flow openingmeans in said second areas joining said second chambers therebyproviding a flow manifold, said successive pairs of plates being spacedapart inwardly of said third areas thereby providing a succession ofthird chambers communicating at their outer ends with said secondchambers and open at their inner ends; means for flowing a first saidfluid radially outwardly through one group of said third chambers fromtheir said open inner ends and radially inwardly through a second groupof said third chambers to said open inner ends of said second group,said flow being by way of said manifold; and means for flowing a secondsaid fluid through said first chambers.

2. The apparatus of claim 1 wherein said second areas of said plates areof small extent, with each plate having a plurality of said second areasarcuately spaced around the plate thereby providing a plurality ofarcuately spaced sets of said second chambers, the second chambers ofeach said set being joined by said fluid flow opening means.

3. The apparatus of claim 2 wherein there are three of said sets equallyspaced around said stack of annular plates.

4. Heat exchanger apparatus for exchange of heat between two fluids,comprising: a plurality of successive pairs of annular plates arrangedin a stack; means joining each pair of plates at first areas adjacenttheir inner edges and at second areas inwardly of their outer edges,each said pair of plates being spaced apart between their said first andsecond areas thereby providing a first chamber in each pair; meansjoining adjacent plates of each of said stacked pairs of plates at thirdareas located outwardly of said second areas, said second areas ofsuccessive pairs of plates being spaced apart thereby providing asuccession of peripherally located second chambers; fluid flow openingmeans in said second areas joining said second chambers therebyproviding a flow manifold, said successive pairs of plates being spacedapart inwardly of said third areas thereby providing a succession ofthird chambers communicating at their outer ends with said secondchambers and open at their inner ends, and said second areas of saidplates are of small extent, with each plate having a plurality of saidsecond areas arcuately spaced around the plate thereby providing aplurality of arcuately spaced sets of said second chambers, the secondchambers of each said set being joined by said fluid flow opening means;means for flowing a first said fluid radially outwardly through onegroup of said third chambers from their said open inner ends andradially inwardly through a second group of said third chambers to saidopen inner ends of said second group, said flow being by way of saidmanifold; means for flowing a second said fluid through said firstchambers; means joining adjacent plates of each of said stacked pairs ofplates at an enclosing fourth area of each plate, each said joined pairof fourth areas being spaced from the adjacent joined pair of fourthareas thereby providing a succession of peripherally located fourthchambers; fluid flow opening means in each said joined pair of fourthareas thereby providing a second manifold; and means for flowing saidfirst said fluid through said second manifold prior to flow through saidthird chambers.

5. The apparatus of claim 4 wherein said fourth areas of said plates areof small extent, with each plate having a plurality of said fourth areasarcuately spaced around the plate thereby providing a plurality ofarcuately spaced sets of said fourth chambers, the fourth chambers ofeach said set being joined by said fluid flow opening means.

6. The apparatus of claim 5 wherein there are three of said sets offourth chambers symmetrically arranged with respect to each other and tosaid second chambers.

7. The apparatus of claim 4 wherein each said third chamber is providedwith an annular agitator fin therein.

8. The apparatus of claim 7 wherein each agitator fin comprises a platewith one set of spaced projections extending from one side thereof and asecond set of spaced projections extending from the other side thereof.

9. The apparatus of claim 8 wherein each said projection is essentiallyfrustoconical with the peak of each projection being located against asaid plate.

10. The apparatus of claim 4 wherein a first of said two fluidscomprises lubricating oil for an engine and a second of said fluidscomprises engine coolant liquid, and there are provided an enclosingcasing having a first inlet for said first fluid to said second manifoldand an outlet from said second manifold to said conduit, means joiningsaid first inlet to said engine for oil flow therethrough, and meansjoining said outlet to said engine for flow of oil therethrough.

11. The apparatus of claim 10 wherein there are provided means dividingsaid inner flow passage means into two adjacent parts, one partcommunicating with said one group of third chambers and the second partcommunicating with the second group of said third chambers, and a flowconduit for said first fluid located in said inner flow passage means,said conduit having a first side opening leading to said first group, anaxially spaced second side opening leading from said second group, andmeans on said conduit separating said groups.

12. The apparatus of claim 11 wherein there are provided a check bypassvalve in said conduit between said first group and said second groupopenable at a preselected pressure equivalent to the viscosity of coldcongealed lubricating oil to bypass said first and second groups of saidthird chambers.

13. The apparatus of claim 1 wherein there are provided separating meansin the plates of said stack for separating said succession of thirdchambers from a series of fourth chambers, means connecting said fourthchambers in series to provide a bypass path exteriorly of said pathcomprising said second and third chambers, and bypass valve means insaid bypass path for opening said path to said first fluid when saidfirst fluid is less than a preselected temperature.

14. The apparatus of claim 13 wherein said stack of plates are arrangedin sets to provide said groups of third chambers and correspondingsecond chambers, each said set being separated from the next by atransverse partition having openings therein interconnecting said secondchambers flow manifold and interconnecting said fourth chambers of saidbypass paths.

15. The apparatus of claim 13 wherein there are provided turbulizers insaid second and third chambers.

16. The apparatus of claim 13 wherein said first fluid comprises anengine lubricating oil and said second fluid comprises a coolant liquid.

17. The apparatus of claim 16 wherein there is provided an oil filtercommunicating with the exits of said path and said bypass path toreceive oil therefrom, and a tube extending through said stack of plateson which said filter is mounted, said tube being connected to the exitfrom said filter for flow of oil therefrom and return to said engine.

18. The apparatus of claim 1 wherein said first chambers are provided bycooperating spacers in each said pair of plates.

19. The apparatus of claim 18 wherein each said spacer comprises araised element in its said plate.

1. Heat exchanger apparatus for exchange of heat between two fluids,comprising: a plurality of successive pairs of plates arranged in astack, each said plate having an outer edge and an inner openingdefining an inner edge; means joining each pair of plates at first areasadjacent their inner edges and at second areas inwardly of their outeredges, each said pair of plates being spaced apart between their saidfirst and second areas thereby providing a first chamber in each pair;means joining adjacent plates of each of said stacked pairs of plates atthird areas located outwardly of said second areas, said second areas ofsuccessive pairs of plates being spaced apart thereby providing asuccession of peripherally located second chambers; fluid flow openingmeans in said second areas joining said second chambers therebyproviding a flow manifold, said successive pairs of plates being spacedapart inwardly of said third areas thereby providing a succession ofthird chambers communicating at their outer ends with said secondchambers and open at their inner ends; means for flowing a first saidfluid radially outwardly through one group of said third chambers fromtheir said open inner ends and radially inwardly through a second groupof said third chambers to said open inner ends of said second group,said flow being by way of said manifold; and means for flowing a secondsaid fluid through said first chambers.
 2. The apparatus of claim 1wherein said second areas of said plates are of small extent, with eachplate having a plurality of said second areas arcuately spaced aroundthe plate thereby providing a plurality of arcuately spaced sets of saidsecond chambers, the second chambers of each said set being joined bysaid fluid flow opening means.
 3. The apparatus of claim 2 wherein thereare three of said sets equally spaced around said stack of annularplates.
 4. Heat exchanger apparatus for exchange of heat between twofluids, comprising: a plurality of successive pairs of annular platesarranged in a stack; means joining each pair of plates at first areasadjacent their inner edges and at second areas inwardly of their outeredges, each said pair of plates being spaced apart between their saidfirst and seCond areas thereby providing a first chamber in each pair;means joining adjacent plates of each of said stacked pairs of plates atthird areas located outwardly of said second areas, said second areas ofsuccessive pairs of plates being spaced apart thereby providing asuccession of peripherally located second chambers; fluid flow openingmeans in said second areas joining said second chambers therebyproviding a flow manifold, said successive pairs of plates being spacedapart inwardly of said third areas thereby providing a succession ofthird chambers communicating at their outer ends with said secondchambers and open at their inner ends, and said second areas of saidplates are of small extent, with each plate having a plurality of saidsecond areas arcuately spaced around the plate thereby providing aplurality of arcuately spaced sets of said second chambers, the secondchambers of each said set being joined by said fluid flow opening means;means for flowing a first said fluid radially outwardly through onegroup of said third chambers from their said open inner ends andradially inwardly through a second group of said third chambers to saidopen inner ends of said second group, said flow being by way of saidmanifold; means for flowing a second said fluid through said firstchambers; means joining adjacent plates of each of said stacked pairs ofplates at an enclosing fourth area of each plate, each said joined pairof fourth areas being spaced from the adjacent joined pair of fourthareas thereby providing a succession of peripherally located fourthchambers; fluid flow opening means in each said joined pair of fourthareas thereby providing a second manifold; and means for flowing saidfirst said fluid through said second manifold prior to flow through saidthird chambers.
 5. The apparatus of claim 4 wherein said fourth areas ofsaid plates are of small extent, with each plate having a plurality ofsaid fourth areas arcuately spaced around the plate thereby providing aplurality of arcuately spaced sets of said fourth chambers, the fourthchambers of each said set being joined by said fluid flow opening means.6. The apparatus of claim 5 wherein there are three of said sets offourth chambers symmetrically arranged with respect to each other and tosaid second chambers.
 7. The apparatus of claim 4 wherein each saidthird chamber is provided with an annular agitator fin therein.
 8. Theapparatus of claim 7 wherein each agitator fin comprises a plate withone set of spaced projections extending from one side thereof and asecond set of spaced projections extending from the other side thereof.9. The apparatus of claim 8 wherein each said projection is essentiallyfrustoconical with the peak of each projection being located against asaid plate.
 10. The apparatus of claim 4 wherein a first of said twofluids comprises lubricating oil for an engine and a second of saidfluids comprises engine coolant liquid, and there are provided anenclosing casing having a first inlet for said first fluid to saidsecond manifold and an outlet from said second manifold to said conduit,means joining said first inlet to said engine for oil flow therethrough,and means joining said outlet to said engine for flow of oiltherethrough.
 11. The apparatus of claim 10 wherein there are providedmeans dividing said inner flow passage means into two adjacent parts,one part communicating with said one group of third chambers and thesecond part communicating with the second group of said third chambers,and a flow conduit for said first fluid located in said inner flowpassage means, said conduit having a first side opening leading to saidfirst group, an axially spaced second side opening leading from saidsecond group, and means on said conduit separating said groups.
 12. Theapparatus of claim 11 wherein there are provided a check bypass valve insaid conduit between said first group and said second group openable ata preselected pressure equivalent to the viscosiTy of cold congealedlubricating oil to bypass said first and second groups of said thirdchambers.
 13. The apparatus of claim 1 wherein there are providedseparating means in the plates of said stack for separating saidsuccession of third chambers from a series of fourth chambers, meansconnecting said fourth chambers in series to provide a bypass pathexteriorly of said path comprising said second and third chambers, andbypass valve means in said bypass path for opening said path to saidfirst fluid when said first fluid is less than a preselectedtemperature.
 14. The apparatus of claim 13 wherein said stack of platesare arranged in sets to provide said groups of third chambers andcorresponding second chambers, each said set being separated from thenext by a transverse partition having openings therein interconnectingsaid second chambers flow manifold and interconnecting said fourthchambers of said bypass paths.
 15. The apparatus of claim 13 whereinthere are provided turbulizers in said second and third chambers. 16.The apparatus of claim 13 wherein said first fluid comprises an enginelubricating oil and said second fluid comprises a coolant liquid. 17.The apparatus of claim 16 wherein there is provided an oil filtercommunicating with the exits of said path and said bypass path toreceive oil therefrom, and a tube extending through said stack of plateson which said filter is mounted, said tube being connected to the exitfrom said filter for flow of oil therefrom and return to said engine.18. The apparatus of claim 1 wherein said first chambers are provided bycooperating spacers in each said pair of plates.
 19. The apparatus ofclaim 18 wherein each said spacer comprises a raised element in its saidplate.